The Ketchum keystone. [volume] (Ketchum, Idaho) 1885-1899, 1887-03-05

of chemical reactions, the ore alone
with suitable proportions of Other
substances, termed fluxes, whereby
the resulting metals and newly
formed chemical compounds (slags
matte, etc. are enabled to separate
by their varying specific gravities
and the gold or silver, or both, al
loyed with either lead or copper
thus procured. 1t may be desig-
mated as a general process. By its
aid the values of any ores can be
extracted, though from the cost OF
the process it may not be able-to do
it profitably in all cases. 1t is the
most costly and at the same time
the most thorough process of all
realizing over 80, and usually at
least 95 per cent of the precious
metals. Usually no ore worth less
than $50 per ton will pay for smelt-
ing. This
| IS A GENERAL FACT,
But there are frequent exceptions.
In Colorado much ore is smelted
that is worth far less, or even half,
that figure. The average of ore in
that state is not over $40 per ton,
but the ore is mined in regions ac-
cessible to the smelters by cheap
transportation, and very much of
their value arises frequently from
their fluxing ingredients. The
business of smelling works is to
extract the wealth from ores by
fusing them. Lead smelling, or
fusion with lead, is carried on for
the purpose of extracting at one
operation whatever Of lead, gold
and silver there may be in an ore, or
in mixture of ores. A portion
of ore mingled with a suitable
amount of flux is exposed to the
action of intense heat, when certain
chemical reactions take place, the
lead sinks to the bottom, carrying
the gold and silver with it, and the
remaining constituents, usually of
no value, melt together and
FORM STAG OR MATTE,
Which are removed from the fur
mace. The valuable product of this
operation is lead bullion, which is
drawn from the furnace and cast
into bars or ingots. Contrary to
the general impression, the smelt-
ing process does not produce the
gold or silver in visible form, but
as an alloy with the lead or copper,
the base metals predominating i'm
mensely. The fluxes added to the
ore and brought under a high de-
gree of heat assist in the melting
and enables it to run, forming
fusible compound in uniting with
the gangue of the ore. The melted
matters which run from a lead
smelling furnace are first, the Stag;
second, the matte; and third, the
bullion. The Stag is composed
mainly of silica combined with iron
oxide and lime, while other sub
stances enter the Stag to some ex
tent. 1t is a black, tough and
heavy substance. breaking unevenly
and we'll suited for road making. 1t
WILL GENERALLY ASSAY
An ounce or two in silver to each
ton. Sulphur, arsenic and anti
mony, which are, especially the
former, large constituents of most
gold and silver ores, are gotten rid
of in blast furnace by combining
them with iron. This at a high
heat produces a black, brittle sub
stance called matte, which is heavier
and melts easier than Stag. 1t ac-
cordingly sinks lower than the Stag
when both are melted and rides
upon the lead bullion which fills
the bottom of the furnace. Arsenic
and anthony combining with iron
produce speiss, which is heavier
than matte and sinks lower in the
furnace, but neither speiss nor
matte are formed unless the ore
sulphur, anthony or ar
senic. Hence, the smelling of ores
which contain neither of these in
gradients is a simpler and usually |
more profitable manner than the
treatment of sulphurets and anti
mony and zinc compounds. The
simplest case in smelling is where
pure lead carbonate is found, or
rather it would be, if it could be
found in apure state. Thepure ore,
IF oxIDIzED COMPLETELY,
Would contain no sulphur, arsenic
or anthony to form speiss and
matte, or gangue to form Stag.
There would be only lead (77 per
cent? with % per cent Of oxygen
and carbonic acid, and it would
only be necessary to heat it with
charcoal or cOke-even wood would
answer-whereby the stuff would
be reduced to metallic lead. Such
operation would be excessively
easy and cheap, and might be car
ried on in a cooking stove or an
open fire. The first impurity apt |
to be met with in treating "carbo-
mates" is silica. If no flux was
used the disagreeable stuff would
not melt, but remain and clog up